Attachment plug



L. M. LAZARUS ATTACHMENT PLUG Oct; 3, 1933.

Fild Sept. 3, 1951 INVENTOR law's M. Lazarus ATTORNEYS g 5L, wwvaw Patented on. 3, 1933 ATTACHMENT PLUG Louis M. Lazarus, Brooklyn, N. Y., assignor oi one-hall to Abraham Abramson Application September 3, l9 3l. Serial No. 560,959

4 Claims.

This invention relates to lighting circuits and more particularly to attachment devices or plugs whereby a plurality of lighting or appliance circuits can be connected to a single outlet box or receptacle.

In my copending application, Serial No. 514,965, filed February 11, 1931, I have disclosed and claimed an attachment device particularly adapted for use with Christmas tree or decorative outfits by means of which two independent elec-, tric circuits may be connected across a power supply circuit through a single outlet box or receptacle, the separate circuits being entirely independent whereby an open circuit, a short circuit in one will have no effect on the other.

The present invention relates to improvements in attachment devices of the character disclosed in my copending application. In the construction disclosed therein I provide a pair of contact blades, each consisting of a pair of conducting members, the conducting members being in the form of separate lamina: of an assembled construction, separated from each other by a layer or sheet of insulation. In the present invention I provide contact blades consisting of a pair oi conducting members, the blade portions of which form only part of the width of the contact blade, and the terminal portions of which are formed of separate layers or laminae. This construction possesses several mechancal advantages, and advantages in manufacture over the construction of my prior application.

The present invention also comprises means for rigidly retaining the contact blades in the blocks of insulating material forming the body of the attachment device. The utility of the feature is not limited in its application to the attachment device herein disclosed, but may be employed to advantage with any type of attachment device or electric plug.

In the accompanying drawing I have shown one i'orm' oi the invention. In this showing:

Fig. 1 is a sectional side view showing the attachment device in conductive engagement with an outlet receptacle with a plug in engagement with one circuit of the device.

Fig. 2 is an end view of one of the insulating blocks of the attachment device;

Fig. 3 is a similar view from the opposite side of the insulating block;

Fig. 4 is a plan view of the contact blade;

Fig. 5 is a sectional view of the contact blade;

Fig. 6 is a plan view taken from the opposite side of the blade; and

Fig. 7 is a diagrammatic representation of two circuits energized through the attachment device of the invention.

Referring to Fig. l oi. the drawing, the attachment device comprises a pair of blocks 1 of insulating material which are of identical con- 0 struction and which carry a pair of contact blades A. The insulating blocks are provided with central openings to receive a bolt 2, the head of whch lies within a recess 3 in the face of one of the blocks and a nut 4 is arranged on the 55 threaded end of the bolt and received in the similar recess in the face of the other block. Each of the insulating blocks consists of a disc 5 having an annular flange 6 and across the center of the block there is provided a substantially H-shaped portion 7 formng a pair of sections for the reception of the contact blades. These sections are provided with openings 8 extending through the face of the disc whereby the contact blade A may project from one side of the attachment device and contact blades from an attachment plug may be inserted in the other side of the attachment device.

The contact blades A, one of which is shown in detail in Figs. 4, 5 and 6, each comprises a 30 pair of current conducting members 9 and 10. At the connecting ends of these conducting members the member 9 fits within a cut-out portion extending longitudinally of the member 10 as shown in Figs. 4 and 6 of the drawing. Each 5 of the conducting members is provided with an offset portion B and the terminal portions D of the two conducting members are of the same width. As shown, the blade end 9 of one conducting member is connected to or forms a part of a terminal portion 11 arranged beneath the terminal portion 12 of the other conducting member when the contact blade is in the position shown in Fig. 5 of the drawing. A strip of insulating material 13 is arranged between the two as terminal portions of the conducting members and a terminal clip 14 is connected to the conducting member 11. A strip of insulating material 15 is then arranged over this terminal clip and lacquer or fiber insulated metal rivets 16 secure the assembled parts together. Lead wires 17 are soldered to the terminal portion 12 of the other conducting member and these lead wires extend over cut-out portions 1'7 in the central portion '7 of the insulating blocks through 135 an opening formed by cut-out portions 18 in the peripheral flange. With this arrangement as shown in Fig. l, the terminal clip 19 of the outlet box or receptacle R is in direct electrical contact with the conducting member 9 and is independently in direct electrical contact with the conducting member 10. The terminal portion 11 of the conducting member 9 is provided with terminal clip 14-and an electric plug 20 may be inserted into the attachment in the usual manner so that the blades 21 of the plug engage the terminal clips 14 to complete one circuit. A mutually independent circuit is, at the same time, completed through conducting members 10, the terminal portions 12 of which are connected to the lead wires 17 which extend through the opening 18 in the side of the attachment device.

The attachment device may be used in various ways but is particularly adapted for use in connection with Christmas tree or decorative outfits in which a plurality of low voltage lamps are connected in series. As shown in Fig. 7, the series connected lamp bulbs 22 may be connected in the circuit of lead wires 1'7 and a similar set of lamp bulbs 23 may be connected through lead wires 24 carried by the electric plug 20. The two circuits are thus maintained entirely independent up to the point at which they are connectedacross the terminal clips 19 at the outlet receptacle. By this arrangement the breakage of a lead wire or a temporary short circuit in one of the set of series connected lamps has no effect upon the energization of the other circuit and the second circuit is maintained energized regardless of a failure at any point in the first circuit.

The improved attachment device may also be employed as a switch for disconnecting one of the lighting circuits from the source of power without entirely withdrawing the device from the receptacle to do so and without employing a separate switch. It has been pointed out that circuits 1'? and 24 are entirely independent, and that the latter is connected to the source of power by contact between the conducting members 9 and the corresponding terminal clips 19 of the outlet box, or receptacle R. Accordingly, inasmuch as the ends of conducting members 9 are spaced from the tips of the corresponding conducting members 10, partial withdrawal of the attachment device from the receptacle R, to disengage conducting members 9 from the corresponding terminal clips 19, disconnects circuit 24 from the source of power. The same result is obtained by partial insertion of the blades into the receptacle. Inasmuch as the tips of the member 10 are in engagement with the corresponding terminal clips 19, only circuit 1'7 is energized. Thus, by a simple act, one of the circuits supplied by the device may be disconnected at will.

In the present invention I also provide means adapted for use with any type of attachment device or electric plug to maintain the contact blades in position. As shown, the terminal end 12 of one of the conducting members is provided with an extension 25 offset at a slight angle as shown in Fig. 5 of the drawing. The inner face of the disc '7 of the plug is provided with a transverse rib 26 arranged between the side walls 2'7 of the central member 7 and thus forming a depression or recess 28 into which the extension 25 fits. This anchors the contact blade in position and holds it rigid.

I claim:

1. In an attachment device of the character described, a pair of contact blades adapted to be inserted in a standard outlet receptacle, each of said blades comprising a pair of conducting members having terminal portions, the blade portion of one of said conducting members having a longitudinal recess, the blade portion of said second conducting member being received in said recess and spaced from the first conducting member, the terminal portion of one of said conducting members being superposed on the terminal portion of the other conducting member, a strip of insulation arranged between said terminal portions, a. terminal clip connected to one of said conducting members and a lead wire connected to the other of said conducting members. 2. In an attachment device of the character described a body of insulating material having recesses therein, a pair of contact blades carried in said recesses and projecting from one face of said body, each of said blades comprising a pair of conducting members having terminal portions, the blade portion of one of said conducting members having a longitudinal recess, the blade portion of said second conducting member 1 being received in said recess and spaced from the first conducting member, the terminal portion of one of said conducting members being superposed on the terminal portion of the other con- 1 ducting member, a strip of insulation arranged between said terminal portions, a terminal clip connected to one of said conducting members and a lead wire connected to the other of said conducting members. l 3. An attachment device of the character described comprising an insulating body formed of a pair of discs of insulating material having peripheral flanges, said discs being adapted to be assembled with the flanges extending toward each 1 other to form said insulating body, a central portion carried by each of said discs having a pair of chambers for the reception of contact blades, a contact blade arranged in each of said chambers, each of said contact blades comprising a 1 pair of conducting members, the blade portion of one of said conducting members having a longitudinal recess, the blade portion of said second conducting member being received in said recess, said blade portions projecting through said insulating body to the exterior thereof, the terminal portion of one of said conducting members being superposed on the terminal portion of the other conducting member, a sheet of insulation arranged between said terminal portions, a terminal clip connected to one of said conducting members, a lead wire connected to the other of said conducting members, and an offset extension formed on said second conducting member and adapted to be received in a recess 1 vin said insulating body to rigidly retain said contact blade in position.

'4. In an attachment device of the character described, the combination of a pair of contact blades adapted to be inserted in a standard outlet receptacle, each of said blades comprising at least two separate mutually electrically isolated conductors for independent connection to two corresponding circuits and for independent engagement with the corresponding contact clips of 1 the receptacle, the tips of the conductors of each blade being spaced apart longitudinally of the blade, whereby the degree of insertion of the blades in the outlet receptacle determines the 1 electrical connection of the circuits corresponding to the conductors of the blades with the source of power.

LOUIS M. LAZARUS. 

